获取公网IP地址

public static String getV4IP(){
String ip = "";
String chinaz = "http://ip.chinaz.com";

StringBuilder inputLine = new StringBuilder();
String read = "";
URL url = null;
HttpURLConnection urlConnection = null;
BufferedReader in = null;
try {
url = new URL(chinaz);
urlConnection = (HttpURLConnection) url.openConnection();
in = new BufferedReader( new InputStreamReader(urlConnection.getInputStream(),"UTF-8"));
while((read=in.readLine())!=null){
inputLine.append(read+"\r\n");
}
//System.out.println(inputLine.toString());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
if(in!=null){
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

Pattern p = Pattern.compile("\\<dd class\\=\"fz24\">(.*?)\\<\\/dd>");
Matcher m = p.matcher(inputLine.toString());
if(m.find()){
String ipstr = m.group(1);
ip = ipstr;
//System.out.println(ipstr);
}
return ip;

}